Backlight module and liquid crystal display

ABSTRACT

The present invention provides a backlight module including a waveguide, a backboard, and a light source, wherein the waveguide is disposed onto the backboard, and the light source is arranged adjacent to a light incident surface of the waveguide, wherein the backlight module includes at least a limiter securely disposed onto the backboard and abuts against to the light source so as to ensure a preset distance between the light source and the incident surface of the waveguide. According to the backlight module and the liquid crystal display, by providing the limiter of the backlight module to abut against the light source, the coupling distance between the light source and the incident surface of the waveguide can be effectively kept constant without being compromised to zero (0) as resulted from expansion under heat or moisture or the accuracy during installation. By this arrangement, the leakage of the backlight module can be readily prevented. In addition, in order to have the limiter readily made as well as reducing the cost, the limiter can be made as a standard part so as to be implemented on the liquid crystal display with different dimension.

FIELD OF THE INVENTION

The present invention relates to a technical field of the liquid crystaldisplay, and more particularly, to a backlight module and the liquidcrystal display incorporated with such a backlight module.

DESCRIPTION OF PRIOR ART

A typical liquid crystal display generally includes a liquid crystalpanel and a backlight module incorporated with the liquid crystal panel.The panel itself does not emit any light, and therefore, the light beamfrom backlight module is used to light up the liquid crystal panel so asto display the images and pattern on the liquid crystal panel. A lightemitting diode (LED) is a typical light source for the backlight module.Generally, a plurality of LEDs are arranged into an array on a printedcircuit board so as to create a light bar or light strip. The LED arrayis then lit up by the power supplied from the driving circuit, and emitan linear light beam and into a light guide plate or waveguide to changethis linear light beam into a surface light to light up the panel.

There is a coupling distance between the light emitting surface of theLED and the waveguide, the coupling distance is used to ensure thedisplaying quality of the liquid crystal display and the utilizationrate of the light beam emitted from the LED. In the actualimplementation, because the waveguide will expand under heat as well ashumid environment when it absorbs moisture, as well as the installationaccuracy, the coupling distance could be reduced to 0 (zero), i.e. thewaveguide is in fact in contact with the LED. Once the waveguide is incontact with the LED, a leakage of light beam will incur.

SUMMARY OF THE INVENTION

In order to resolve the existing technical problem of prior art, thepresent invention provides a backlight module including a waveguide, abackboard, and a light source, wherein the waveguide is disposed ontothe backboard, and the light source is arranged adjacent to a lightincident surface of the waveguide, wherein the backlight module includesat least a limiter securely disposed onto the backboard and abutsagainst to the light source so as to ensure a preset distance betweenthe light source and the incident surface of the waveguide.

In addition, wherein the limiter includes a connector and a pusherdisposed on the connector, the connector is arranged between thewaveguide and the backboard, wherein the connector is rooted onto thebackboard so as to support the waveguide, wherein the connector abutsagainst the light source such that the abutting portion is close to thelight source.

In addition, wherein the backlight module further includes a heatsinkarranged between the connector and the backboard, and which includes arecess, a platform and a side, and wherein the connector includes abackbone, and a carrier extending from the backbone, and an inclinedtransition located between the backbone and the carrier, wherein thebackbone is disposed within the recess, and a locking device passingthrough the backbone, the recess and the backboard to interlock thebackbone, the recess and the backboard together, wherein the carrier isdisposed onto the platform so as to carrier the waveguide, and thecarrier abutting against the light source and the inclined transition isdisposed onto the side of the recess.

In addition, wherein the fixing device is a screw, and the through holeis a threaded hole.

In addition, wherein the light source includes a plurality of spot lightsource and a light circuit board interconnected to the spot lightsources, wherein the pusher includes a bracket and at least a tabsupported by the bracket, wherein the heatsink further includes asidewall on which the light circuit board is installed thereon, whereinthe bracket is disposed onto the carrier to limit a transversal movementof a reflector disposed between the waveguide and the carrier, whereinthe tab is disposed between two adjacent spot light sources and whereinthe dimension of the tab is larger than the dimension of the spot lightsource 310 along the direction of the coupling distance.

In addition, wherein heat conductive paste or glue is applied betweenthe circuit board of the light source and the sidewall

In addition, wherein the limiter is integrally formed.

In addition, wherein the limiter is made from metallic material.

In addition, wherein the limiter is made from plastic material.

It is a further objective of the present invention to provide a liquidcrystal display, including a backlight module and a liquid crystal panelarranged with respect to the backlight module which provides light beamto the liquid crystal panel, wherein, the backlight module describedabove.

According to the backlight module and the liquid crystal display, byproviding the limiter of the backlight module to abut against the lightsource, the coupling distance between the light source and the incidentsurface of the waveguide can be effectively kept constant without beingcompromised to zero (0) as resulted from expansion under heat ormoisture or the accuracy during installation. By this arrangement, theleakage of the backlight module can be readily prevented. In addition,in order to have the limiter readily made as well as reducing the cost,the limiter can be made as a standard part so as to be implemented onthe liquid crystal display with different dimension.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configurational and perspective view of a limiter made inaccordance with the present invention;

FIG. 2 is a partial and illustrational view showing the limiter made inaccordance with the present invention is mounted onto a backlightmodule;

FIG. 3 is a partial, cross sectional view of the backlight module madein accordance with the present invention; and

FIG. 4 is an illustrational view of a liquid crystal display made inaccordance with the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In the description given to the preferred embodiment in view of theaccompanied drawings, like elements will be given with similar numeralreferences. Detailed description will be given to the embodiment inlight of the accompanied drawings. In the description given below, inorder to avoid any confusion resulted from the unnecessary descriptionto any configurational structure or function of prior arts, thosedescription in view of the prior art configuration and function has beenomitted.

FIG. 1 is a configurational and perspective view of a limiter made inaccordance with the present invention; FIG. 2 is a partial andillustrational view showing the limiter made in accordance with thepresent invention is mounted onto a backlight module; and FIG. 3 is apartial, cross sectional view of the backlight module made in accordancewith the present invention.

Referring to FIGS. 1, 2 and 3, a backlight module made in accordancewith the present invention includes a waveguide 100, a backboard 200, alight source 300, and a limiter 400.

Wherein the waveguide 100 is disposed onto the backboard 200, and thewaveguide 100 includes an incident surface 110 and the light source 300is disposed adjacent to the incident surface 110. The limiter 400 ismounted onto the backboard 200 and abuts against the light source 300 soas to keep a constant distance between the light source 300 and theincident surface 110. In the current invention, the number of thelimiter 400 is not limited to what disclosed in FIG. 2. The actualquantity of the limiter 400 can be two or more than two in accordancewith the actual requirements.

Substantially, the limiter 400 includes a connector 410 and a pusher 420disposed onto the connector 410. Wherein the connector 410 is disposedbetween the waveguide 100 and the backboard 200. The connector 410 ismounted onto the backboard 200 and supports the waveguide 100. Theconnector 410 is mounted adjacent to the light source 300 so as to havethe pusher 420 is proximate to the light source 300.

The light source 300 includes a plurality of spot light source 310, suchas the light emitting diode, and a light circuit board 320, such as aprinted circuit board interconnected to those spot light sources 310.The pusher 420 includes a bracket 421 and a pair of tabs 422 which aredisposed adjacent to a plurality of light sources 310. Accordingly, whenthe waveguide 100 experiences an expansion under heat or situatedmoisture or an accuracy issue during the installation, the incidentsurface 110 of the waveguide 100 will then move closer to the lightsource 300 and the coupling distance is shortened. However, with thelimiter 400 disposed between the light source 300 and the incidentsurface 110, the tab 422 of the pusher 420 will prevent the incidentsurface 110 moving toward light source 300. As a result, the couplingdistance between the incident surface 110 and the light source 300 iskept constant. In order to keep the coupling distance between theplurality of spot light sources 310 and the incident surface 110 evenfurther constant, preferably, the dimension of the tab 422 is largerthan the dimension of the spot light source 310 along the direction ofthe coupling distance. The function of the bracket 421 will not befurther described.

The connector 410 includes a backbone 411 and a carrier 412 extendingfrom the backbone 411, and an inclined transition 413 arranged betweenthe backbone 411 and the carrier 412. It should be understandable thatthe backbone 411 and the carrier 412 are located on different planes.The carrier 412 is used to support and carrier the waveguide 100, andthe backbone 411 is mounted onto the backboard 200. The interconnectionbetween the backbone 411 and the backboard 200 and the function of theinclined transition 413 will be detailedly described herebelow. Thebracket 421 of the pusher 420 is mounted onto the carrier 412 so as tolimit a reflector 700 from moving transversally, and the reflector 700is arranged between the waveguide 100 and the carrier 412.

In the preferred embodiment of the present invention, in order to havethe backlight module 10 have a better heat dissipation performance, thebacklight module 10 further includes a heatsink 500 which is mountedbetween the connector 410 and the backboard 200. The heatsink 500includes a recess 510, a pair of platforms 520, 530 and an inclined side540. The height of the platform 530 is higher than the platform 520. Thefunction of the platforms 520, 530 will be detailedly describedherebelow.

The connector 411 is disposed within the recess 510 and a screw 610 isused to interlock the backbone 411, the recess 510 and the backboard 200in which a threaded hole 620 is defined. By this arrangement, thebackbone 411, the recess and the backboard 200 can be securelyinterlocked together. The carrier 412 is mounted onto the platform 520to carry the reflector 700 and the waveguide 100. The carrier 412 abutsdirectly to the light circuit board 320 so as to have the tabs 422disposed between every two adjacent spot light sources 310,respectively. The platform 530 directly supports the reflector 700 andthe waveguide 100. The height of the platform 520 pluses the thicknessof the carrier 412 equals to the height of the platform 530. Accordinglythe reflector 700 and the waveguide 100 can be kept horizontally. Theinclined transition 413 is disposed onto the inclined side 540.

It should be noted that the screw 610 can be also replaced with othersuitable devices, such as a rivet. The threaded hole 620 can be replacedby a through hole once a rivet is used. In addition, bonding agent canbe arranged between the backbone 411 and the recess 510, and between therecess 510 and the backboard 200. With the function of the bondingagent, the backbone 411, the recess 510 and the backboard 200 can besecurely interlocked together.

Furthermore, in the preferred embodiment of the present invention, theheatsink 500 further includes a sidewall 550. As a result, the lightcircuit board 320 can be attached to the sidewall 550, and the heatbuilt-up on the light circuit board 320 because of powering the energyfor the spot light source 310 can be readily dissipated to the backboard200 through the heatsink 500, and the heat will be further dissipated tothe ambient environment through the backboard 200. By this arrangement,the heat generated by both the spot light source 310 and the lightcircuit board 320 can be effectively dissipated. Of course, the heatsink500 can exclude the sidewall 550, while a supporting frame can beinstalled on the backboard 200 in a position corresponding to the lightsource 300. The supporting frame can be used to install the light source300. The supporting frame can be readily attached to the backboard 200with the existing technology generally available to the skill in theart. The present invention will not be limited thereto.

The light circuit board 320 and the sidewall 550 of the heatsink 500 canbe deployed with heat conductive paste or glue 800 so as to securelyattach the light circuit board 320 to the sidewall 50. In addition, thedeployment of the heat conductive paste or glue can effectivelydissipate the heat generated by the light circuit board 320. Of course,the light circuit board 320 can be attached to the sidewall 500 by waysof other mechanic measurements, such as screw or the like. The presentinvention is not limited merely thereto.

It should be noted that in the current embodiment, the limiter 400 canbe integrally formed. Of course, the limiter 400 can be configured withdifferent components interconnected together. The present inventionshould not limit thereto.

In addition, according to the preferred embodiment of the presentinvention, in order to further dissipate the heat generated from thelight circuit board 320 and the spot light source 310 to the heatsink500, the limiter 400 can be made from metallic material, such aszinc-plated steel plate (SECC) or galvanized high carbon steel (SGCC) oraluminum alloy (AL5052). Of course, the present invention will not belimited thereto, as the limiter can be made from plastic material, suchas the white or transparent polycarbonate (PC) or polymethylmethacrylate (PMMA).

FIG. 4 discloses an illustrational view of a liquid crystal display madein accordance with the present invention.

As shown in FIG. 4, a liquid crystal display 1 made in accordance withthe present invention includes a backlight module 10 and a liquidcrystal panel 20 disposed relative to the backlight module 10. Thebacklight module 10 provides light beam to the liquid crystal panel 20such that images and pattern on the liquid crystal panel 20 can beshown.

In conclusion, by the limiter 400 of the backlight module 10 abutsagainst the light source 300, the coupling distance between the lightsource 300 and the incident surface 110 of the waveguide 100 can beeffectively kept constant without being compromised to zero (0) asresulted from expansion under heat or moisture or the accuracy duringinstallation. By this arrangement, the leakage of the backlight module10 can be readily prevented. In addition, in order to have the limiter400 readily made as well as reducing the cost, the limiter 400 can bemade as a standard part so as to be implemented on the liquid crystaldisplay with different dimension.

Even embodiments of the present invention have been described, but notintending to impose any unduly constraint to the appended claims. Anymodification of equivalent structure or equivalent process madeaccording to the disclosure and drawings of the present invention, orany application thereof, directly or indirectly, to other related fieldsof technique, is considered encompassed in the scope of protectiondefined by the claims of the present invention.

The invention claimed is:
 1. A backlight module including a waveguide, abackboard, and a light source, wherein the waveguide is disposed ontothe backboard, and the light source is arranged adjacent to a lightincident surface of the waveguide, wherein the backlight module includesat least a limiter securely disposed onto the backboard and abutsagainst to the light source so as to ensure a preset distance betweenthe light source and the incident surface of the waveguide; wherein thelimiter includes a connector and a pusher disposed on the connector, theconnector is arranged between the waveguide and the backboard, whereinthe connector is rooted onto the backboard so as to support thewaveguide, wherein the connector abuts against the light source suchthat the abutting portion is close to the light source; wherein aheatsink is arranged between the connector and the backboard andincludes a recess, a platform and a side; and the connector includes abackbone, and a carrier extending from the backbone, and an inclinedtransition located between the backbone and the carrier; and wherein thebackbone is disposed within the recess, and a locking device passingthrough the backbone, the recess and the backboard to interlock thebackbone, the recess and the backboard together, wherein the carrier isdisposed onto the platform so as to carrier the waveguide, and thecarrier abutting against the light source and the inclined transition isdisposed onto the side of the recess.
 2. The backlight module as recitedin claim 1, wherein the fixing device is a screw, and the through holeis a threaded hole.
 3. The backlight module as recited in claim 1,wherein the light source includes a plurality of spot light source and alight circuit board interconnected to the spot light sources, whereinthe pusher includes a bracket and at least a tab supported by thebracket, wherein the heatsink further includes a sidewall on which thelight circuit board is installed thereon, wherein the bracket isdisposed onto the carrier to limit a transversal movement of a reflectordisposed between the waveguide and the carrier, wherein the tab isdisposed between two adjacent spot light sources and wherein thedimension of the tab is larger than the dimension of the spot lightsource 310 along the direction of the coupling distance.
 4. Thebacklight module as recited in claim 3, wherein heat conductive paste isapplied between the circuit board of the light source and the sidewall.5. The backlight module as recited in claim 3, wherein heat conductiveglue is applied between the circuit board of the light source and thesidewall.
 6. The backlight module as recited in claim 1, wherein thelimiter is integrally formed.
 7. The backlight module as recited inclaim 1, wherein the limiter is made from metallic material.
 8. Thebacklight module as recited in claim 1, wherein the limiter is made fromplastic material.